The present invention relates to a power transmission belt and a belt transmission system including the power transmission belt.
It is known that para-aramid fibers can be used as a cord of a power transmission belt.
Patent Document 1 (Japanese Unexamined Patent Publication No. 2005-265106) discloses using a plied yarn with a total fiber fineness of 9900 dtex as a cord of a double cogged V belt.
This plied yarn consists of three primarily-twisted yarns, each of which is obtained by primarily twisting a bundle of para-aramid fibers with a fiber fineness of 1650 dtex, in one direction at a twist coefficient of 4.3. Then, these three primarily-twisted yarns are secondarily twisted in the opposite direction to the primary twist at a twist coefficient of 3.6, thereby obtaining the plied yarn. According to Patent Document 1, the twist coefficient is calculated by the following equation:twist coefficient=0.496×number of twists(twists/10 cm)×(fiber fineness (dtex))1/2 